Monus

Summary

In mathematics, monus is an operator on certain commutative monoids that are not groups. A commutative monoid on which a monus operator is defined is called a commutative monoid with monus, or CMM. The monus operator may be denoted with the minus sign, "$-$", because the natural numbers are a CMM under subtraction. It is also denoted with a dotted minus sign, "$\mathbin{\dot{-}}$", to distinguish it from the standard subtraction operator.